Water quality -- Determination of ammonium -- Part 1: Manual spectrometric method

Document Number: NL ISO 7150 1 : 2009
Sector: Food Technology
TC: No
ICS: 13.060.50
1.1 Substance determined This part of ISO 7150 specifies a manual spectrometric method for the determination of ammonium in water. NOTE — An automated spectrometric method for the determination of ammonium will form the subject of ISO 7150/2. 1.2 Type of sample The method is applicable to the analysis of potable water, and most raw and waste waters. Application to excessively coloured or saline waters shall be preceded by distillation (see clause 10). For interferences, see clause 9. 1.3 Range An ammonium nitrogen concentration, ϱN of up to 1 mg/l, using the maximum test portion of 40 ml, can be determined. Much higher concentrations can be determined by taking smaller test portions. 1.4 Limit of detection1) When using cells of optical path length 40 mm and a 40 ml test portion, the limit of detection lies within the range ϱN = 0,003 to 0,008 mg/l. 1.5 Sensitivity1) Using a 40 ml test portion and a cell of optical path length 40 mm, ϱN = 0,200 mg/l gives an absorb